Is there any valid use for javascript's encodeURI function?
As far as I can tell, when you are trying to make a HTTP request you should either have:
a complete URI
some fragment you want to put in a URI, which is either a unicode string or UTF-8 byte sequence
In the first case, obviously nothing needs to be done to request it. Note: if you actually want to pass it as a parameter (e.g ?url=http...) then you actually have an instance of the second case that happens to look like a URI.
In the second case, you should always convert a unicode string into UTF-8, and then call encodeURIComponent to escape all characters before adding it to a URI. (If you have a UTF-8 byte sequence instead of a unicode string you can skip the convert-to-utf8 step).
Assuming I havent missed anything, I can't see a valid use for encodeURI. If you use it, it's likely you've constructed an invalid URI and then attempted to "sanitize" it after the fact, which is simply not possible since you don't know which characters were intended literally, and which were intended to be escaped.
I have seen a lot of advice against using escape(), but don't see anybody discouraging encodeURI. Am I missing a valid use?
I have a blog post which answers this question in a lot of detail.
You should never use encodeURI to construct a URI programmatically, for the reasons you say -- you should always use encodeURIComponent on the individual components, and then compose them into a complete URI.
Where encodeURI is almost useful is in "cleaning" a URI, in accordance with Postel's Law ("Be liberal in what you accept, and conservative in what you send.") If someone gives you a complete URI, it may contain illegal characters, such as spaces, certain ASCII characters (such as double-quotes) and Unicode characters. encodeURI can be used to convert those illegal characters into legal percent-escaped sequences, without encoding delimiters. Similarly, decodeURI can be used to "pretty-print" a URI, showing percent-escaped sequences as technically-illegal bare characters.
For example, the URL:
http://example.com/admin/login?name=Helen Ødegård&gender=f
is illegal, but it is still completely unambiguous. encodeURI converts it into the valid URI:
http://example.com/admin/login?name=Helen%20%C3%98deg%C3%A5rd&gender=f
An example of an application that might want to do this sort of "URI cleaning" is a web browser. When you type a URL into the address bar, it should attempt to convert any illegal characters into percent-escapes, rather than just having an error. Software that processes URIs (e.g., an HTML scraper that wants to get all the URLs in hyperlinks on a page) may also want to apply this kind of cleaning in case any of the URLs are technically illegal.
Unfortunately, encodeURI has a critical flaw, which is that it escapes '%' characters, making it completely useless for URI cleaning (it will double-escape any URI that already had percent-escapes). I have therefore borrowed Mozilla's fixedEncodeURI function and improved it so that it correctly cleans URIs:
function fixedEncodeURI(str) {
return encodeURI(str).replace(/%25/g, '%').replace(/%5B/g, '[').replace(/%5D/g, ']');
}
So you should always use encodeURIComponent to construct URIs internally. You should only never use encodeURI, but you can use my fixedEncodeURI to attempt to "clean up" URIs that have been supplied from an external source (usually as part of a user interface).
encodeURI does not encode the following: , / ? : # & = + $ # whereas encodeURIComponent does.
There are a myriad of reasons why you might want to use encodeURI over encodeURIComponent, such as assigning a URL as a variable value. You want to maintain the URL but encode paths, query string and hash values. Using encodeURIComponent would make the URL invalid.
Related
I'm having an issue with react router encoding spaces but not ampersands. So localhost:8080/you & me is encoded to be localhost:8080/you%20&%20me instead of localhost:8080/you%20%26%20me and I'm using a wonky hack to decode then re-encode everything. I was wondering if anyone can recommend a better solution.
Do not use non-alphanumeric characters in the URL. Some characters like &, /, ?, and = have special meanings in URLs. Even though react-router does not throw an error when you create a route component with a & in the url, as you have noticed, you'll end up with wonky behavior. It's best practice to avoid strange edge cases. You can read more about allowed characters in a url here.
As a workaround, you can achieve nearly the same URL with localhost:8080/you-and-me. This is a safe url without spaces and special characters. It's also human readable, which anything with spaces wouldn't be easily readable as it would be encoded.
I was reading about URL encode inside browser. I know it is done to send URL over internet. But when I see this encoding inside address bar, it seems that only some characters being encoded. However, when I copy and paste inside notepad, all SPECIAL CHARACTERS seem to be encoded. What we see in address browser is fake? Actually all characters are encoded? Do browsers use javascript function encodeURI() for this purpose?
Yes, what the address bar shows is often not the actual URL. Most browsers decode encoded characters to display a more friendly looking URL, and to allow you to read the URL as actual characters, which may or may not be useful.
However, some characters look extremely similar to other characters, like the cyrillic letter А (U+0410) which is virtually indistinguishable from the latin letter A (U+0041). To avoid confusion and/or phishing attacks, letters which are easily confused may not be decoded.
I'm receiving response from an API that contains name strings with special letters like 'é'.
Then I need to make a request to another API with query string containing this name with 'é'. API is third-party service which doesn't understand this letters.
encodeURIComponent doesn't help, server still returns an error.
I would like to replace special characters with existing alternatives like 'é'=>'e', is there a library or some ready solution for this purpose?
Those characters are called diacritic (more specifically this tiny stroke above the e).
Here's a JS lib https://github.com/superjoe30/diacritics
You need to modify it slightly in order to use it without any module loader.
Just replace exports.remove with sth. like window.removeDiacrits and then
str = removeDiacrits(str);
and it's probably a good idea to wrap the code in a IIFE.
Did you tried the encodeURI
encodeURI - To encode an URL
encodeURIComponent - to encode the query string parameter
I'm currently learning JavaScript, and I don't understand why it is important to encode URLs.
>>> var url = 'http://www.packtpub.com/scr ipt.php?q=this and that';
>>> encodeURI(url);
"http://www.packtpub.com/scr%20ipt.php?q=this%20and%20that"
For instance, in this example what purpose would it serve to change the first URL to the latter one.
It depends on what you're going to be doing with that URL.
When you just use a document.location = url, you don't want it encoded.
If you plan on passing that URL as a variable, then yes you want it encoded or it will confuse the browser. For instance:
http://www.someurl.com?myFavwebsite=http://www.stackoverflow.com?someParam=test.
See how that could be confusing to the browser?
By the way, never use a space in a url or php file. i've always found that to cause unnecessary stress. :)
Only a limited number of characters are allowed in URLs, according to the RFC 3986 standard. If you have a space in a URL, for example, this will make the URL invalid unless you encode it.
Often, browsers can deal with URLs that are not properly encoded by doing the encoding themselves, but that's not something you should rely on as a web developer.
URL encoding is also critical when using URLs as parameters of another URL. In this case the reserved characters of the URL need to be encoded, not just the non-permitted characters. For this, however, you don't use encodeURI, but encodeURIComponent.
I am working on a browser plugin that takes the URL of the current page or any selected link as a parameter and send it to our server.
When characters of the basic latin alphabet are present in the url (like http://en.wikipedia.org/wiki/Vehicle), the plugin works fine. However, when the URL contains characters from another alphabet such as http://ru.wikipedia.org/wiki/Коляска the plugin does not work, I do use the encodeURIComponentmethod but that does not seem to solve the issue. Any idea?
Thanks,
Olivier.
You probably want to use encodeURI/decodeURI, if you are trying to take a full URI with non-ASCII characters and translate it into its encoded form. These preserve special URI characters, such as : and /, instead of escaping them; it only escapes non-ASCII characters and characters that are invalid in URIs. Thus, they do essentially the same thing as typing in the address bar or putting a URI in an <a href="..."> (though the behavior might vary somewhat between browser, and isn't exactly the same).
encodeURIComponent is intended for encoding only a single component of a URI, replacing special characters that are meaningful in URIs, so that you can use the component as a query parameter or path component in a longer URI.
This one says it covers UTF-8. http://www.webtoolkit.info/javascript-url-decode-encode.html. Might solve your problem